The present invention relates to certain branched alkoxy-subsituted 2-aminopyridines that exhibit activity as nitric oxide synthase (NOS) inhibitors, to pharmaceutical compositions containing them and to their use in the treatment and prevention of central nervous system disorders, inflammatory disorders, septic shock and other disorders.
There are three known isoforms of NOSxe2x80x94an inducible form (I-NOS) and two constitutive forms referred to as, respectively, neuronal NOS (N-NOS) and endothelial NOS (E-NOS). Each of these enzymes carries out the conversion of arginine to citrulline while producing a molecule of nitric oxide (NO) in response to various stimuli. It is believed that excess nitric oxide (NO) production by NOS plays a role in the pathology of a number of disorders and conditions in mammals. For example, NO produced by I-NOS is thought to play a role in diseases that involve systemic hypotension such as toxic shock and therapy with certain cytokines. It has been shown that cancer patients treated with cytokines such as interleukin 1 (IL-1), interleukin, 2 (IL-2) or tumor necrosis factor (TNF) suffer cytokine-induced shock and hypotension due to NO produced from macrophages, i.e., inducible NOS (I-NOS), see Chemical and Engineering News, Dec. 20, p. 33, (1993). I-NOS inhibitors can reverse this. It is also believed that I-NOS plays a role in the pathology of diseases of the central nervous system such as ischemia. For example, inhibition of I-NOS has been shown to ameliorate cerebral ischemic damage in rats, see Am. J. Physiol., 268, p. R286 (1995)). Suppression of adjuvant induced arthritis by selective inhibition of I-NOS is reported in Eur. J. Pharmacol., 273, p. 15-24 (1995).
NO produced by N-NOS is thought to play a role in diseases such as cerebral ischemia, pain, and opiate tolerance. For example, inhibition of N-NOS decreases infarct volume after proximal middle cerebral artery occlusion in the rat, see J. Cerebr. Blood Flow Metab., 14 p. 924-929 (1994). N-NOS inhibition has also been shown to be effective in antinociception, as evidenced by activity in the late phase of the formalin-induced hindpaw licking and acetic acid-induced abdominal constriction assays, see Br. J. Pharmacol., 110, p. 219-224 (1993). Finally, opioid withdrawal in rodents has been reported to be reduced by N-NOS inhibition, see Neuropsychopharmacol., 13, p. 269-293 (1995).
This invention relates to compounds of the formula 
wherein X is CHOH; CH2; or CHR10, wherein R10 (ethylene or n-propylene), together with the CH of CHR10, the adjacent CH2 group, and the nitrogen of NR1R2, forms a five or six membered saturated ring, in which case R2 is a single bond;
R1, R2 (when X is not CHR10), R3 and R4 are selected, independently, from (C1-C6) alkyl, tetrahydronaphthalene, aryl and aralkyl, wherein said aryl and the aryl moiety of said aralkyl is phenyl or naphthyl and the alkyl moiety is straight or branched and contains from 1 to 6 carbon atoms, and wherein said (C1-C6) alkyl and said tetrahydronaphthalene and the aryl moiety of said aralkyl may optionally be substituted with from one to three substituents, preferably from zero to two substituents, that are selected, independently, from halo (e.g., chloro, fluoro, bromo, iodo), nitro, hydroxy, cyano, amino, (C1-C4) alkoxy, and (C1-C4) alkylamino;
or R1 and R2 (when X is not CHR10), together with the nitrogen to which they are attached, form a piperazine, piperidine or pyrolidine ring or a azabicyclic ring containing from 6 to 14 ring members, from 1 to 3 of which are nitrogen and the rest of which are carbon, wherein examples of said azabicyclic rings are the following 
wherein R5 and R6 are selected from hydrogen, (C1-C6)alkyl, phenyl, naphthyl, (C1-C6)alkyl-C(xe2x95x90O)xe2x80x94, HC(xe2x95x90O)xe2x80x94, (C1-C6)alkoxy-(Cxe2x95x90O)xe2x80x94, phenyl-C(xe2x95x90O)xe2x80x94, naphthyl-C(xe2x95x90O)xe2x80x94, and R8R9NC(xe2x95x90O)xe2x80x94 wherein R8 and R9 are selected, independently, from hydrogen and (C1-C6)alkyl;
R7 is selected from hydrogen, (C1-C6)alkyl, phenyl, naphthyl, phenyl-(C1-C6)alkyl- and naphthyl(C1-C6)alkyl-;
and wherein said piperazine, piperidine and pyrrolidine rings may optionally be substituted with one or more substituents, preferably with from zero to two substituents that are selected, independently, from (C1-C6)alkyl, amino, (C1-C6) alkylamino, [di-(C1-C6)alkyl]amino, phenyl substituted 5 to 6 membered heterocyclic rings containing from 1 to 4 rings nitrogen atoms, benzoyl, benzoylmethyl, benzylcarbonyl, phenylaminocarbonyl, phenylethyl and phenoxycarbonyl, and wherein the phenyl moieties of any of the foregoing substituents may optionally be substituted with one or more substituents, preferably with from zero to two substituents, that are selected, independently, from halo, (C1-C3)alkyl, (C1-C3)alkoxy, nitro, amino, cyano, CF3 and OCF3;
and wherein R3 and R4, together with the carbon to which they are attached, form an optionally substituted carbocyclic ring of from 3 to 8 members;
and the pharmaceutically acceptable salts of such compounds.
The present invention also relates to the pharmaceutically acceptable acid addition salts of compounds of the formula I. The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the aforementioned base compounds of this invention are those which form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as the hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, acetate, lactate, citrate, acid citrate, tartrate, bitartrate, succinatate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate [i.e., 1,1-methylene-bis-(2-hydroxy-3-naphthoate)] salts.
The term xe2x80x9calkylxe2x80x9d, as used herein, unless otherwise indicated, includes saturated monovalent hydrocarbon radicals having straight, branched or cyclic moieties or combinations thereof.
The term xe2x80x9cone or more substituentsxe2x80x9d, as used herein, refers to a number of substituents that equals from one to the maximum number of substituents possible based on the number of available bonding sites.
The terms xe2x80x9chaloxe2x80x9d and xe2x80x9chalogenxe2x80x9d, as used herein, unless otherwise indicated, include chloro, fluoro, bromo and iodo.
More specific embodiments of the present invention include:
(a) compounds of the formula I wherein R1, R2, R3 and R4 are selected, independently, from (C1-C6)alkyl;
(b) compounds of the formula I wherein R3 and R4 are selected, independently, from (C1-C6)alkyl, and R1 and R2, together with the nitrogen to which they are attached, form a ring;
(c) compounds of the formula I wherein one of R1 and R2 is selected from (C1-C6)alkyl, and the other is selected from phenyl or phenyl-(C1-C6)alkyl;
(d) compounds of the formula I wherein R1 and R2, together with the nitrogen to which they are attached, form a piperazine, piperidine or pyrrolidine ring; and
(e) compounds of the formula I wherein R1 and R2 are selected, independently from (C1-C6)alkyl, and R3 and R4, together with the carbon to which they are attached, form a ring.
Examples of specific preferred embodiments of this invention are:
6-[2-Isopropoxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Isobutoxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Isobutoxy-4-((4-dimethylaminoethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Isopropoxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyridin-2-ylamine;
1-[4-(6-Amino-pyridin-2-y)-3-isopropoxy-phenyl]-2-(4-phenethyl-piperazin-1-yl)-ethanol;
6-[2-Cyclopentyloxy-4-((4-dimethylaminoethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclopentyloxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine; and the pharamaceutically acceptable salts of the foregoing compounds.
Other examples of specific embodiments of this invention are:
6-[2-Cyclohexyloxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclobutyloxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclopropyloxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Isopentyloxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Isohexyloxy-4-((4-phenethylpiperazin-1-yl)-ethyl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclopentyloxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclohexyloxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclobutyloxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyridin-2-ylamine;
6-[2-Cyclopropyloxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyridin-2-ylamine,
6-[2-Isopentyloxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyridin-2-ylamine;
6-[2-Isohexyloxy-(N-(2-methyl)propyl)-4-(pyrrolidin-3-yl)-phenyl]-pyrdin-2-ylamine;
1-[4-(6-Aminopyrdin-2-yl)-3-isobutoxy-phenyl]-2-(4-phenethyl-piperazin-1-yl)-ethanol;
1-[4-(6-Amino-pyridin-2-yl)-3-isopropoxy-phenyl]-2-(6,7-dimethoxy-tetrahydroisoquinol-2-yl)-ethanol;
1-[4-(6-Amino-pyridin-2-yl)-3-isopropoxy-phenyl]-2-(4-dimethylamino-piperidin-1-yl)-ethanol;
1-[4-(6-Amino-pyridin-2-yl)-3-isopropoxy-phenyl]-2-(dimethylamino)-ethanol; and
1-[4-(6-Amino-pyridin-2-yl)-3-cyclopenyloxy-phenyl]-2-(4-phenethyl-piperazin-1-yl)-ethanol;
and the pharmaceutically acceptable salts of the foregoing compounds.
The present invention also relates to a pharmaceutical composition for treating or preventing a condition selected from the group consisting of migraine, inflammatory diseases (e.g., asthma and psoriasis), stroke, acute and chronic pain, hypovolemic shock, traumatic shock, reperfusion injury, Crohn""s disease, ulcerative colitis, septic shock, multiple sclerosis, AIDS associated dementia, neurodegenerative diseases, neuron toxicity, Alzheimer""s disease, Parkinson""s disease, chemical dependencies and addictions, emesis, epilepsy, anxiety, psychosis, depression, (e.g., major depressive disorder and dysthymia), head trauma, adult respiratory distress syndrome (ARDS), morphine induced tolerance and withdrawal symptoms, inflammatory bowel disease, osteoarthrits, rheumatoid arthritis, ovulation, dilated cardiomyopathy, acute spinal cord injury, Huntington""s disease, glaucoma, macular degeneration, diabetic neuropathy, diabetic nephropathy and cancer in a mammal, including a human, comprising an amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof that is effective in treating or preventing such condition, and a pharmaceutically acceptable carrier.
The present invention also relates to a method of treating or preventing a condition selected from the group consisting of migraine, inflammatory diseases (e.g., asthma and psoriasis), stroke, acute and chronic pain, hypovolemic shock, traumatic shock, reperfusion injury, Crohn""s disease, ulcerative colitis, septic shock, multiple sclerosis, AIDS associated dementia, neurodegenerative diseases, neuron toxicity, Alzheimer""s disease, chemical dependencies and addictions (e.g., dependencies on drugs, alcohol and nicotine), Parkinson""s disease, emesis, epilepsy, anxiety, psychosis, depression, (e.g., major depressive disorder and dysthymia), head trauma, adult respiratory distress syndrome (ARDS), morphine induced tolerance and withdrawal symptoms, inflammatory bowel disease, osteoarthritis, rheumatoid arthritis, ovulation, dilated cardiomyopathy, acute spinal cord injury, Huntington""s disease, glaucoma, macular degeneration, diabetic neuropathy, diabetic nephropathy and cancer in a mammal, including a human, comprising administering to said mammal an amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof, that is effective in treating or preventing such condition.
The present invention also relates to a pharmaceutical composition for inhibiting nitric oxide synthase (NOS) in a mammal, including a human, comprising an NOS inhibiting effective amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.
The present invention also relates to a method of inhibiting NOS in a mammal, including a human, comprising administering to said mammal a NOS inhibiting effective amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof.
The present invention also relates to a pharmaceutical composition for treating or preventing a condition selected from the group consisting of migraine, inflammatory diseases (e.g., asthma and psoriasis), stroke, acute and chronic pain, hypovolemic shock, traumatic shock, reperfusion injury, Crohn""s disease, ulcerative colitis, septic shock, multiple sclerosis, AIDS associated dementia, neurodegenerative diseases, neuron toxicity, Alzheimer""s disease, chemical dependencies and addictions (e.g., dependencies on drugs, alcohol and nicotine), Parkinson""s disease, emesis, epilepsy, anxiety, psychosis, depression, (eg., major depressive disorder and dysthymia), head trauma, adult respiratory distress syndrome (ARDS), morphine induced tolerance and withdrawal symptoms, inflammatory bowel disease, osteoarthritis, rheumatoid arthritis, ovulation, dilated cardiomyopathy, acute spinal cord injury, Huntingting""s disease, glaucoma, macular degeneration, diabetic neuropathy, diabetic nephropathy and cancer in a mammal, including a human, comprising a NOS inhibiting effective amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.
The present invention also relates to a method of treating or preventing a condition selected from the group consisting of migraine, inflammatory diseases (e.g., asthma and psoriasis), stroke, acute and chronic pain, hypovolemic shock, traumatic shock, reperfusion injury, Crohn""s disease, ulcerative colitis, septic shock, multiple sclerosis, AIDS associated dementia, neurodegenerative diseases, neuron toxicity, Alzheimer""s disease, chemical dependencies and addictions (e.g., dependencies on drugs, alcohol or nicotine), Parkinson""s disease, emesis, epilepsy, anxiety, psychosis, depression, (e.g., major depressive disorder and dysthymia), head trauma, adult respiratory distress syndrome (ARDS), morphine induced tolerance and withdrawal symptoms, inflammatory bowel disease, osteoarthritis, rheumatoid arthritis, ovulation, dilated cardiomyopathy, acute spinal cord injury, Huntington""s disease, glaucoma, macular degeneration, diabetic neuropathy, diabetic nephropathy and cancer in a mammal, including a human, comprising administering to said mammal a NOS inhibiting effective amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof.
Compounds of formula I have chiral centers and therefore may exist in diffenent enantiomeric and diastereomeric forms. This invention relates to all optical isomers and all stereoisomers of compounds of the formula I and mixtures thereof, and to all pharmaceutical compositions and methods of treatment defined above that contain or employ them, respectively.
Formula I above includes compounds identical to those depicted but for the fact that one or more hydrogen, carbon or other atoms are replaced by isotopes thereof. Such compounds may be useful as research and diagnostic tools in metabolism pharmacokinetic studies and in binding assays.
The compounds of the formula I may be prepared as described in the following reaction schemes and discussion. Unless otherwise indicated, X, R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 and structural formula I in the reaction schemes and discussion that follow are defined as above. 
Referring to Scheme 1, the compound of formula II is reacted with a compound of the formula CHR3R4Br or CHR2R4l and potassium carbonate, in a solvent such as acetonitrile, at about the reflux temperature of the reaction mixture, to convert the hydroxy group of formula II into a group having the formula xe2x80x94OCHR3R4. The resulting compound is then reduced, at about room temperature, using hydrogen gas in the presence of 10% palladium on carbon, in an ethanol solvent, to form 3-OCHR3R4-4-aminotoluene, which is then reacted with sodium nitrite and cuprous bromide in concentrated sulfuric acid to form 3-OCHR3R4-4-bromotoluene.
The 3-OCHR3R4-4-bromotoluene produced in the foregoing reaction is then cooled to about xe2x88x9270xc2x0 C. in dry tetrahydrofuran (THF), and a solution of n-butyl lithium is added to it. The resulting solution is then treated with triethyl borate and allowed to warm to room temperature to form the compound of formula III.
The compound of formula III is reacted with the compound of formula IV to form the compound of formula V. This reaction is generally carried out in an aqueous ethanol solvent, in the presence of sodium carbonate and tetrakistriphenylphosphine palladium, at about the reflux temperature of the reaction mixture.
The compound of the formula VII can be formed in the following manner. First, the compound of formula V is reacted with N-bromosuccinimide (NBS) and bis-(1-cyano-1-aza)-cyclohexane (formula VI) in carbon tetrachloride and refluxed for about 8 hours, with additional portions of the initiator being added at about 1, 2 and 4 hours. After evaporation of the solvent, the product of this reaction is reacted with triethylammonium cyanide in methylene chloride at about room temperature to form the compound of formula VII.
Saturation of a solution of the compound of formula VII in ethanol with hydrogen chloride, followed by refluxing the mixture and then heating in aqueous hydrochloric acid, yields the compound of formula VII. Hydrolysis of the compound of formula VII yields the corresponding compound of formula IX. The base hydrolysis is typically carried out using an alkali metal or alkaline earth metal hydroxide in a mixture of ethanol and water at a temperature from about room temperature to about the reflux temperature of the solvent.
The compound of the formula IX that is formed in the preceding step can be converted into the compound of formula I in the following manner. First, the compound of formula IX is reacted with the appropriate compound of the formula R2R1NH and N-ethyl-N-dimethylaminopropyl carbodiimide (EDAC) in the presence of a base. Examples of suitable bases are those selected from trialkylamines, alkali metal carbonates and alkaline earth metal carbonates. This reaction is typically conducted in a solvent such as acetonitrile, methylene chloride or N,N-dimethylformamide (DMF), at a temperature from about room temperature to about 100xc2x0 C., preferably at about room temperature. Preferably, the reaction is conducted in the presence of a catalytic additive such as N-hydroxysuccinamide or hydroxybenzotriazole.
The product of the foregoing reaction is then reduced using methods well known to those of skill in the art. For example, the reduction can be carried out using lithium aluminum hydride in tetrahydrofuran, with or without aluminum chloride, or using borane methyl sulfide in tetrahydrofuran, at a temperature of about xe2x88x9278xc2x0 C. to about 0xc2x0 C., preferably at about xe2x88x9270xc2x0 C., to yield the desired compound of formula I.
Referring to Scheme 2, 4-bromo-3-fluorotoluene is first converted to the boronic acid derivative and then coupled to 6-bromo-2-(t-butylcarbonylamino)pyridine to form compound of the formula X in the following manner. A halogen-metal exchange reaction is carried out on 3-fluoro4-bromotoluene in tetrahydrofuran, ether, dimethoxyethane, hexane or another suitable ethereal or hydrocarbon solvent, at a temperature from xe2x88x92100xc2x0 C. to about room temperature, using butyl lithium or another suitable alkyl lithium reagent, followed by reaction with a borate triester such as triethyl or triisopropyl borate, for about 1 to about 48 hours at a temperature from about xe2x88x92100xc2x0 C. to about the reflux temperature. The intermediate boronic acid derivative is then converted into the compound of formula X in an aqueous ethanol solvent, in the presence of sodium carbonate and tetrakistriphenylphosphine palladium, at about the reflux temperature of the reaction mixture, using 6-bromo-2-(t-buylcarbonylamino)pyridine as the coupling partner. The compound of formula X is then converted into a compound of the formula XI by displacement of the fluoro group from the alcohol with a suitable alkoxide, which is formed in a solvent such as dimethylformamide, tetrahydrofuran or dioxane, and a metal hydride such as sodium hydride, at a temperature from about room temperature to about the reflux temperature, for a period of about 5 minutes to about 5 hours. The reaction with the compound of formula X is carried out in this reaction system at a temperature from room temperature to about the reflux temperature for a period from about 1 to about 48 hours.
The compound of formula XI is then converted into the corresponding compound of the formula IX in the following manner. First, the compound of formula XI is reacted with N-bromosuccinimide (NBS) and bis-(1-cyano-1-aza)-cyclohexane (formula VI in Scheme 1) in carbon tetrachloride and refluxed for about 8 hours, with additional portions of the initiator being added after about 1, 2 and 4 hours, to brominate the methyl group of such compound. After evaporation of the solvent, the product of this reaction is reacted with triethylammonium cyanide in methylene chloride at about room temperature to form the corresponding compound wherein the bromo substituent is replaced by cyano. The resulting cyano derivative is then hydrolyzed to form the corresponding compound of formula IX. The base hydrolysis is typically carried out using an alkali metal or alkaline earth metal hydroxide in a mixture of ethanol and water at a temperature from about room temperature to about the reflux temperature of the solvent.
The compound of the formula IX that is formed in the preceding step can be converted into the compound of formula I in the following manner. First, the compound of formula IX is reacted with the appropriate compound of the formula R2R1NH and N-ethyl-N-dimethylaminopropyl carbodiimide (EDAC) in the presence of a base. Examples of suitable bases are those selected from trialkylamines, alkali metal carbonates and alkaline earth metal carbonates. This reaction is typically conducted in a solvent such as acetonitrile, methylene chloride or N,N-dimethylformamide (DMF), at a temperature from about room temperature to about 100xc2x0 C., preferably at about room temperature. Preferably, the reaction is conducted in the presence of a catalytic additive such as N-hydroxysuccinamide or hydroxybenzotriazole.
The product of the foregoing reaction is then reduced using methods well known to those of skill in the art to yield the desired compound of formula I. For example, the reduction can be carried out using lithium aluminum hydride in tetrahydrofuran, with or without aluminum chloride, or using borane methyl sulfide in tetrahydrofuran, at a temperature of about xe2x88x9278xc2x0 C. to about 0xc2x0 C., preferably at about xe2x88x9270xc2x0 C.
Compounds of the formula I wherein X is CHOH can be prepared using a procedure analogous to that described in Example 7 of this application. Compounds of the formula I wherein X is part of a five or six membered saturated ring may be prepared using a procedure analogous to that described in Example 6.
The starting materials used in the procedures of Schemes 1 and 2 are either commercially available, known in the art or readily obtainable form known compounds by methods that will be apparent to those skilled in the art.
The preparation of other compounds of the formula I not specifically described in the foregoing experimental section can be accomplished using combinations of the reactions described above that will be apparent to those skilled in the art.
In each of the reactions discussed or illustrated above, pressure is not critical unless otherwise indicated. Pressures from about 0.5 atmospheres to about 5 atmospheres are generally acceptable, and ambient pressure, i.e., about 1 atmosphere, is preferred as a matter of convenience.
The compounds of formulae I (xe2x80x9cthe active compounds of this inventionxe2x80x9d) which are basic in nature are capable of forming a wide variety of different salts with various inorganic and organic acids. Although such salts must be pharmaceutically acceptable for administration to animals, it is often desirable in practice to initially isolate a compound of the formula I from the reaction mixture as a pharmaceutically unacceptable salt and then simply convert the latter back to the free base compound by treatment with an alkaline reagent and subsequently convert the latter free base to a pharmaceutically acceptable acid addition salt. The acid additon salts of the active base compounds of this invention are readily prepared by treating the base compound with a substantially equivalent amount of the chosen mineral or organic acid in an aqueous solvent medium or in a suitable organic solvent, such as methanol or ethanol. Upon careful evaporation of the solvent, the desired solid salt is readily obtained.
The active compounds of this invention and their pharmaceutically acceptable salts are useful as NOS inhibitors i.e., they possess the ability to inhibit the NOS enzyme in mammals, and therefore they are able to function as therapeutic agents in the treatment of the aforementioned disorders and diseases in an afflicted mammal.
The active compounds of this invention and their pharmaceutically acceptable salts can be administered via either the oral, parenteral or topical routes. In general, these compounds are most desirably administered in dosages ranging from about 0.01 to about 250 mg per day, in single or divided doses (i.e., from 1 to 4 doses per day), although variations will necessarily occur depending upon the species, weight and condition of the subject being treated and the particular route of administration chosen. However, a dosage level that is in the range of about 0.07 mg to about 21 mg per kg of body weight per day is most desirably employed. Variations may nevertheless occur depending upon the species of animal being treated and its individual response to said medicament, as well as on the type of pharmaceutical formulation chosen and the time period and interval at which such administration is carried out. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed without causing any harmful side effect, provided that such larger doses are first divided into several small doses for administration throughout the day.
The active compounds of the invention may be administered alone or in combination with pharmaceutically acceptable carriers or diluents by either of the three routes previously indicated, and such administration may be carried out in single or multiple doses. More particularly, the novel therapeutic agents of this invention can be administered in a wide variety of different dosage forms, i.e., they may be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, aqueous suspensions, injectable solutions, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media and various non-toxic organic solvents, etc. Moreover, oral pharmaceutical compositions can be suitably sweetened and/or flavored. In general, the therapeutically-effective compounds of this invention are present in such dosage forms at concentration levels ranging from about 5.0% to about 70% by weight.
For oral administration, tablets containing various excipients such as microcrystalline cellulose, sodium citrate, calcium carbonate, dicalcium phosphate and glycine may be employed along with various disintegrants such as starch (and preferably corn, potato or tapioca starch), alginic acid and certain complex silicates, together with granulation binders like polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc are often very useful for tabletting purposes. Solid compositions of a similar type may also be employed as fillers in gelatin capsules; preferred materials in this connection also include lactose or milk sugar as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration, the active ingredient may be combined with various sweetening or flavoring agents, coloring matter or dyes, and, if so desired, emulsifying and/or suspending agents as well, together with such diluents as water, ethanol, propylene glycol, glycerin and various like combinations thereof.
For parenteral administration, solutions of an active compound of the present invention in either sesame or peanut oil or in aqueous propylene glycol may be employed. The aqueous solutions should be suitably buffered (preferably pH greater than 8) if necessary and the liquid diluent first rendered isotonic. These aqueous solutions are suitable for intravenous injection purposes. The oily solutions are suitable for intraarticular, intramuscular and subcutaneous injection purposes. The preparation of all these solutions under sterile conditions is readily accomplished by standard pharmaceutical techniques well known to those skilled in the art.
Additionally, it is also possible to administer the active compounds of the present invention topically when treating inflammatory conditions of the skin and this may be done by way of creams, jellies, gels, pastes, patches, ointments and the like, in accordance with standard pharmaceutical practice.
The ability of compounds of the formulae I to inhibit NOS may be determined using procedures described in the literature. The ability of compounds of the formulae I to inhibit endothelial NOS may be determined by using the procedures described by Schmidt et al. in Proc. Natl. Acad. Sci. U.S.A., 88, pp. 365-369 (1991) and by Pollock et al., in Proc. Natl. Acad. Sci. U.S.A., 88, pp. 10480-10484 (1991). The ability of compounds of the formulae I to inhibit inducible NOS may be determined using the procedures described by Schmidt et al., in Proc. Natl. Acad, Sci. U.S.A., 88 pp. 365-369 (1991) and by Garvey et al. in J. Biol. Chem., 269, pp. 26669-26676 (1994). The ability of the compounds of the formulae I to inhibit neuronal NOS may be determined using the procedure described by Bredt and Snyder in Proc. Natl. Acad. Sci. U.S.A., 87, 682-685 (1990).
The title compound of Example 1 below exhibited an IC50 less than 10 xcexcM for inhibition of either inducible or neuronal NOS.
The present invention is illustrated by the following examples. It will be understood, however, that the invention is not limited to the specific details of these examples. Melting points are uncorrected. Proton nuclear magnetic resonance spectra (1H NMR) and C13 nuclear magnetic resonance spectra were measured for solutions in deuterochloroform (CDCl3) or in CD3OD or CD3SOCD3 and peak, positions are expressed in parts per million (ppm) downfield from tetramethylsilane (TMS). The peak shapes are denoted as follows: s, singlet; d, doublet; t, triplet; q, quartet, m, multiplet, b, broad.